This section is from the book "Commercial Gardening Vol4", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
A popular South European shrub, 6-8 ft. high, with narrow grey-green leaves, whitish beneath, and spikes of whitish or pale-purple flowers. It grows well in ordinary soil in warm sheltered spots, and may be raised from cuttings, layers, or seeds. The oil is much used in perfumery.